1. Field of the Invention
Embodiments of the present invention relate to systems and methods for indicating a quality of grouped items and, more particularly, to a quality of grouped items generated, for example, within a material recovery facility (MRF).
2. Background Description
Waste management companies provide residential, commercial and municipal waste management and recycling services for communities and organizations. Customers can include single residences, companies, or entire towns. Municipalities often contract with or otherwise engage a waste management service provider to handle both its municipal solid waste (MSW) and/or as its recycling services. MSW is garbage, refuse, and other discarded materials that result from residential, commercial, industrial, and/or community activities. MSW does not include banned waste, animal waste used as fertilizer, or sewage sludge.
Municipalities also encourage, or even require, recycling of selected materials including, but not limited to, paper, cans, plastic bottles, and glass. Generally, these materials are picked up either by a waste management company or a by municipality and taken to a material recovery facility (MRF), which is a facility that separates, processes, stores, and re-sells recoverable materials that have been collected.
At a MRF, materials are initially sorted by a variety of mechanical and manual means. The materials are further sorted and grouped by category and, within the category, sorted by quality. For example, clear glass is separated from colored glass, paper is separated from cardboard, and plastics are separated by type and color. Then glass is separated into various colors, where some colors are recycled more than other colors. When the final sorts are finished, some materials, such as plastic, steel, aluminum, paper, and cardboard are compressed into bales by large presses, and sold to customers who convert the baled material into consumer products.
Problems associated with the above described material sorting process are that it is material specific, inefficient to implement, and expensive. For example, the initial sort for identifying each item of waste is done by a person, which makes sorting inefficient and expensive. Another example is sorting plastics by using an optical device to determine various types of plastic. However, such optical devices are specific to the plastic, expensive to implement, useful only for a range of plastic recyclables and are limited to line-of-sight identification. Finally, eddy-current systems are useful only in connection with metal recyclables. With line-of-sight identification systems there are problems such as false identifications, and a process that is time and labor intensive. Thus, although these various processes and techniques are helpful for recycling, the end result is that errors in sorting occur, and sorted material is often commingled with un-separable, non-recyclable material and items.
Another problem with the material sorting processes is that municipalities continue to encourage and, in many cases, require recycling and reuse of recoverable materials, resulting in a growing amount of potentially recyclable material. This recyclable material becomes more commingled with non-recyclable materials as less care is taken to recycle properly by those required to recycle, leading to the aforementioned sorting issues of being material specific, inefficient to implement, and expensive. In the end, the quality of the sorted materials that are produced as commodities for sale declines, sometimes significantly. For example, many recoverable materials are converted into large bales before being sold, and these bales often become contaminated with non-recyclable material. The final recyclables to be sold may become so contaminated that a customer becomes unsatisfied with the quality (e.g., a low ratio of recyclables to non-recyclables and/or contaminated materials). The recycler may therefore need to accept a downgraded price (lower quality product) or returned product.
In view of the foregoing, we have discovered that there is a need to provide an accurate and verifiable measurement of the quality (e.g., percent purity) of a commodity within, for example, a bale of recovered material(s).